As it is well known, an IC Card includes a main device, including a processor and a memory portion, and a plurality of contact pads. The main device may be connected to a read-write device via a main interconnection including the contact pads. According to the ISO 7816-3 standard, the read-write device and the main device may communicate in a half duplex mode, sending and receiving data to and from the read-write device over an I/O contact pad of the main interconnection.
In particular, the IC Card is an electrically passive component; when it is connected to the read-write device it begins a power-up sequence, receiving a clock signal from the read write device and executing an operating system, for communicating with the read-write device. More particularly, the read-write device acts as a master device with respect to the IC Card, sending commands over the I/o contact pad, for example for executing an application or retrieving data stored inside the memory portion of the IC Card. The IC Card responds as a slave device, processing the commands and returning results to the read-write device over the I/O contact pad.
A disadvantage of such IC Card is that it may communicate only with the read write device, since it is powered by the read write device and, when powered, it may transmit data only over the I/O contact pad that is the unique channel available for communication. In other words, when the IC Card is powered, it is a slave device that can only establish a communication with the read write device, receiving command from the I/O contact pad and transmit data over the same I/O contact pad.
Moreover, the IC Card cannot establish a secondary communication with another device since it cannot use the I/O contact pad for the secondary communication, without damaging the ISO 7816 communication protocol with the read write device.
The problem at the basis of the present invention is that of providing an IC Card supporting a main interconnection between the read-write device and the main device, for exchanging main data over the I/O contact pad according to the ISO 7816-3 protocol, at the same time providing a secondary interconnection with an additional device, for transmitting secondary data, avoiding any modification to the main interconnection and to the ISO 7816-3 protocol, and overcoming the limitations of the current IC Card that narrow its use as a slave device with respect to the read-write device and prevent its communication with other additional devices.